Embodiments according to the present invention relate to apparatuses and methods for providing a reduced representation based on a time-domain RF signal (RF=radio frequency) which may be used in a broad range of applications, for instance, when analyzing radio or cable-bound transmissions. It may, furthermore, be used when transmitting digitized RF signals between components of a more complex system.
In many fields of modern technology, a limiting factor is the available bandwidth for transporting data, signals; and other pieces of information between components, systems, or other circuits. In many cases, the maximum data throughput of such a link and the capacity of storage systems will limit a maximum available RF bandwidth, which can be processed by such a system.
In state of the art receiver systems, the digitized data are typically transmitted over a data link using a complex-valued I/Q data with a fixed resolution of, for instance, 16, 24, or 32 bits for both the imaginary and the real parts of the samples. When using complex or complex-valued I/Q data for transportation of data, a signal component being in-phase with a reference oscillation and a component with a phase-shift of 90° will be transmitted, which are referred to as in-phase (=I) data and quadrature (=Q) data.
This method is, however, rather inefficient. First of all, the signals to be transmitted usually comprise a significant amount of redundant information. An extreme example is a spectrum of a continuous wave (CW) signal, where most frequency bins in a frequency representation contain very little, or ideally, no energy, while only one frequency bin comprises a contribution with a higher value. The energy in the bins which only contains very little energy is typically caused by the receiver noise floor and other noise sources. Nevertheless, all bins are transmitted by transmitting the time-domain signal with the same word length, e.g. 32-bits for each of the two components.